Software recognition of ATM cell boundaries, commonly known as ATM cell delineation, on an incoming serial data stream is a computationally intensive task. Typically a method such as that outlined in the ITU-T I.432.1 specification is required. In this multiple single bit shifts followed by a boundary check per shift are employed. The reason for delineating the cells is to allow the content of the cells to be decoded. If a given RISC processor is required to delineate a plurality of serial ATM cell streams the processing requirements for the delineation algorithm will leave little computational resource for other tasks. Furthermore, if the RISC processor is of low performance (i.e. a low number of instructions processed per second) it may not be possible to process a plurality of serial ATM cell streams on that engine. Similar problems can be encountered in any embodiment of data requiring delineation based on data integrity checking. As such the present invention is relevant to more than just ATM cell delineation.
US 2002/0141450 relates to a scheme for cell delineation in hardware. This method processes bytes received from the data stream in multiple parallel byte processing engines that process a first set of bytes during the first cycle and a second set of bytes during a second cycle.
U.S. Pat. No. 5,768,274 a shows a scheme for cell delineation in hardware. This patent discloses a cell multiplexer having time divisional multiplexed cell delineation functions.
US 2003/0048803 relates to another hardware method for cell delineation. This application discloses a transmission convergence sub layer circuit and operating method for an asynchronous receiver.
U.S. Pat. No. 6,269,096 relates to yet another hardware method of cell delineation. Here blocks are received and transmitted for ATM cell delineation. The received block has a plurality of cell delineation blocks which are selected by a bus controller in order to delineate the ATM cells.
None of the prior art relates to any software implementation of ATM cell delineation. Accordingly none of the prior appreciate the problems of ATM cell delineation in the software environment and certainly go nowhere to solving those problems.